EP0355782B1 - Nichtanzapfbare optische Monomodefaser und diese Faser verwendendes Übertragungsverfahren - Google Patents

Nichtanzapfbare optische Monomodefaser und diese Faser verwendendes Übertragungsverfahren Download PDF

Info

Publication number
EP0355782B1
EP0355782B1 EP89115437A EP89115437A EP0355782B1 EP 0355782 B1 EP0355782 B1 EP 0355782B1 EP 89115437 A EP89115437 A EP 89115437A EP 89115437 A EP89115437 A EP 89115437A EP 0355782 B1 EP0355782 B1 EP 0355782B1
Authority
EP
European Patent Office
Prior art keywords
information
index
annular
light
micrometers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP89115437A
Other languages
English (en)
French (fr)
Other versions
EP0355782A1 (de
Inventor
Jacques Auge
Pascale Beaufume
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alcatel Lucent SAS
Original Assignee
Alcatel SA
Alcatel Alsthom Compagnie Generale dElectricite
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alcatel SA, Alcatel Alsthom Compagnie Generale dElectricite filed Critical Alcatel SA
Publication of EP0355782A1 publication Critical patent/EP0355782A1/de
Application granted granted Critical
Publication of EP0355782B1 publication Critical patent/EP0355782B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/02—Optical fibres with cladding with or without a coating
    • G02B6/036—Optical fibres with cladding with or without a coating core or cladding comprising multiple layers
    • G02B6/03616—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference
    • G02B6/03638—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 3 layers only
    • G02B6/03644—Optical fibres characterised both by the number of different refractive index layers around the central core segment, i.e. around the innermost high index core layer, and their relative refractive index difference having 3 layers only arranged - + -

Definitions

  • the present invention relates to an optical fiber according to the preamble of claim 1 for the transmission of information and more particularly the protection of such a transmission against attempted diversion.
  • the present invention aims only to make this diversion more difficult and / or, if it is carried out, to warn the sender and / or the recipient of the information.
  • an information-carrying signal is most often put in electrical form, in the form of a radiated electromagnetic wave, or in the form of a guided optical wave, most often in a single-mode optical fiber.
  • a fiber conventionally comprises a core carrying the signal and a monolithic optical sheath with the core, surrounding the latter, having a lower refractive index, and consequently constituting the seat of a so-called evanescent wave which also carries the signal. but is normally only detectable at a very short distance from the heart.
  • This optical sheath is itself surrounded by an outer sheath of a different nature providing mechanical and chemical protection.
  • single-mode fiber is increasingly taking a leading role, including in local networks.
  • the guided optical nature of the signal makes intrusion more difficult than on conventional electrical wires or on a radiated electromagnetic link. This is why the present invention applies to this guided optical nature and more precisely to guidance by single-mode fiber.
  • Abrasion methods make it possible to get even closer to the core and are also usable for information hijacking since monomode fiber couplers are based on this principle.
  • annular auxiliary guide is used to minimize the optical dispersion along the fiber and is not intended to guide an optical control signal.
  • the present invention aims to obtain effective protection of the information transmitted in a single-mode fiber.
  • FIG. 1 represents a perspective view of a fiber according to the invention.
  • FIG. 2 represents a diagram of the variation of the refractive index at a point of a section of this fiber as a function of the distance from this point to the axis of this fiber.
  • a central core of the fiber is shown in 2, an information confinement sheath in 4, an annular core in 6 and an auxiliary confinement sheath in 8, the radius of this central core 2 being a and the radii inside and outside of the annular core 6 being b and c, respectively (the central core 2 and the confinement sheath 4 thus constituting a central guide; and the annular core 6 and the confinement sheaths 4 and 8 an annular guide, respectively).
  • the refractive index profile is simply that known as "index jump”, both for the central guide and for the annular guide.
  • central guide central core 2 and containment sheath 4
  • central core 2 and containment sheath 4 The definition of the central guide (central core 2 and containment sheath 4) is compatible with conventional single-mode fibers optimized for light whose wavelength is located in the spectral window centered at about 1.3 micrometers, and the annular guide can propagate some well guided modes having no interaction with the central core mode.
  • a scrambling wave reception system is installed at the end of the line. Any draw of energy can therefore be detected as an anomaly on the level of power received. This system also makes it possible to act on the transmission of the information wave, which further increases the level of protection of this optical line.
  • a fiber according to the invention has the advantage of propagating a single mode in the central guide (fundamental mode LP01) and about ten modes in the annular guide of which only the first half is well guided ( reduced attenuation over a long length), at least with the set of structure parameters a, b, c, and Dn given above for an application in the 1.3 micrometer window.
  • this fiber lies in the fact that, in the whole range of parameter values indicated, only the fundamental mode remains well confined in the core, the higher order modes being well located in the annular core. It has been observed that a modification of the structure parameters within this range eliminates (or adds) one or two modes of propagation in the annular guide.
  • conventional single-mode fibers optimized to 1.3 micrometers there are certain constraints on the parameters a and Dn to guarantee single-mode operation and to prevent the first higher-order mode LP11 from being able to propagate. In the fiber according to the invention, this problem is absent since this mode like all higher order modes is somehow "sucked" by the annular guide.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Communication System (AREA)
  • Optical Couplings Of Light Guides (AREA)
  • Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
  • Optical Integrated Circuits (AREA)

Claims (7)

  1. Gegen Anzapfen von Informationen geschützte Lichtleitfaser, die aufweist:
    - einen zentralen Kern (2), in dem sich eine informationstragende Lichtwelle, die ein Informationssignal tragt, fortpflanzt, wobei der Brechungsindex dieses zentralen Kerns ein Index des zentralen Kerns ist,
    - eine optische Hülle (4) zum Einschließen einer Information, die diesen zentralen Kern monolithisch umgibt und einen Brechungsindex aufweist, der ein Index einer informationseinschließenden Hülle ist und der geringer als der Index des zentralen Kerns ist, um die informationstragende Welle in diesem zentralen Kern einzuschließen und diese Welle nur gedämpft in diese Hülle eindringen zu lassen, wodurch ein zentraler Lichtleiter gebildet wird,
    - einen ringförmigen Kern (6), der die informationseinschließende Hülle monolithisch umgibt und einen Brechungsindex aufweist, der ein Index eines ringförmigen Kerns ist und größer ist als der Index der informationseinschließenden Hülle, um einer Hilfs-Lichtwelle zu erlauben, sich in diesem ringförmigen Kern auszubreiten,
    - und eine optische Hilfs-Einschluß-Hülle (8), die den ringförmigen Kern monolithisch umgibt und einen Brechungsindex aufweist, der ein Index einer Hilfshülle ist und der niedriger ist als der Index des ringförmigen Kerns, um in Zusammenwirkung mit der informationseinschließenden Hülle die Hilfswelle in diesem ringförmigen Kern einzuschließen, wodurch ein ringförmiger Leiter gebildet wird,
    dadurch gekennzeichnet, daß der zentrale Lichtleiter einen Monomodeleiter für das Licht darstellt, das sich darin in Form einer geführten informationstragenden Lichtwelle ausbreiten soll, während der ringförmige Lichtleiter (6) einen schwach mehrmodalen Wellenleiter für das Licht gleicher Wellenlänge wie die informationstragende Welle bildet, das sich in diesem ringförmigen Leiter in Form einer geführten Hilfs-Lichtwelle ausbreitet.
  2. Faser nach Anspruch 1, dadurch gekennzeichnet, daß die Anzahl der Ausbreitungsmodi des Hilfslichts im ringförmigen Lichtleiter zwischen 2 und 10 liegt.
  3. Faser nach Anspruch 1, dadurch gekennzeichnet, daß der Radius des zentralen Kerns (2) zwischen 3,8 und 4,6 Mikrometer liegt, während die Dicke der informationseinschließenden Hülle zwischen 20 und 24 Mikrometer, die Dicke des ringförmigen Kerns (6) zwischen 2,7 und 3,3 Mikrometer liegt und die Brechungsindices des zentralen Kerns und des ringförmigen Kerns im Vergleich zum Brechungsindex der informationseinschließenden Hülle Indexüberschüsse (Dn) zwischen 45 und 55 Tausendstel aufweisen.
  4. Faser nach Anspruch 1, dadurch gekennzeichnet, daß die Wellenlänge des Lichts zwischen 0,5 und 3 Mikrometer liegt.
  5. Faser nach Anspruch 4, dadurch gekennzeichnet, daß die Wellenlänge des Lichts etwa 1,3 Mikrometer im Fall einer Faser auf der Basis von Siliziumoxid beträgt.
  6. Verfahren zur Übertragung eines informationstragenden Lichtsignals mit Schutz vor Informationsanzapfungen über die Lichtleitfaser gemäß Anspruch 1, dadurch gekennzeichnet, daß ein informationstragendes Lichtsignal in den zentralen Kern (2) der Lichtleitfaser eingespeist wird, das sich dort dann in Form einer geführten Lichtwelle ausbreitet, und daß in den ringförmigen Kern (6) der Lichtleitfaser ein Hilfslicht der gleichen Wellenlänge wie das informationstragende Licht eingespeist wird, das sich dann im ringförmigen Kern in Form einer geführten Hilfslichtwelle ausbreitet, um dort eine Störwelle und/oder eine Welle zur Erfassung eines Anzapfens zu bilden.
  7. Verfahren nach Anspruch 6, dadurch gekennzeichnet, daß die Hilfswelle ein Störsignal trägt.
EP89115437A 1988-08-26 1989-08-22 Nichtanzapfbare optische Monomodefaser und diese Faser verwendendes Übertragungsverfahren Expired - Lifetime EP0355782B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8811286A FR2635876B1 (fr) 1988-08-26 1988-08-26 Fibre optique monomode protegee contre le detournement d'informations transmises et procede de transmission utilisant cette fibre
FR8811286 1988-08-26

Publications (2)

Publication Number Publication Date
EP0355782A1 EP0355782A1 (de) 1990-02-28
EP0355782B1 true EP0355782B1 (de) 1994-01-26

Family

ID=9369550

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89115437A Expired - Lifetime EP0355782B1 (de) 1988-08-26 1989-08-22 Nichtanzapfbare optische Monomodefaser und diese Faser verwendendes Übertragungsverfahren

Country Status (4)

Country Link
US (1) US4986629A (de)
EP (1) EP0355782B1 (de)
DE (1) DE68912684T2 (de)
FR (1) FR2635876B1 (de)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2738430B1 (fr) * 1990-09-21 1998-03-13 Alsthom Cge Alcatel Procede et dispositif de transmission d'information sur fibre optique avec detection et/ou localisation d'intrusion
US5177803A (en) * 1991-04-29 1993-01-05 Corning Incorporated Coaxial optical fiber coupler transmitter-receiver apparatus and method of making same
US6381045B1 (en) * 1998-06-24 2002-04-30 Lucent Technologies Inc. Method and apparatus for bidirectional communication over a single optical fiber
EP3018507A1 (de) * 2014-11-06 2016-05-11 Alcatel Lucent Vorrichtung und Verfahren zur Erfassung eines Angriffs auf die Integrität einer Übertragungslinie eines optischen Signals
US10033148B2 (en) 2016-02-04 2018-07-24 Lawrence Livermore National Security, Llc Waveguide design for line selection in fiber lasers and amplifiers
US10348050B2 (en) 2016-02-04 2019-07-09 Lawrence Livermore National Security, Llc Nd3+fiber laser and amplifier
KR102279322B1 (ko) * 2019-04-08 2021-07-21 한양대학교 산학협력단 다중 진단 및 치료 카테터와 이를 포함하는 카테터 시스템

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4000416A (en) * 1975-07-11 1976-12-28 International Telephone And Telegraph Corporation Multi-core optical communications fiber
US4134642A (en) * 1976-04-16 1979-01-16 Northern Telecom Limited Optical fibre with increased security
CA1205307A (en) * 1981-12-07 1986-06-03 Venkata A. Bhagavatula Low dispersion, low-loss single-mode optical waveguide

Also Published As

Publication number Publication date
EP0355782A1 (de) 1990-02-28
DE68912684D1 (de) 1994-03-10
US4986629A (en) 1991-01-22
FR2635876B1 (fr) 1992-10-16
DE68912684T2 (de) 1994-05-05
FR2635876A1 (fr) 1990-03-02

Similar Documents

Publication Publication Date Title
EP1722256B1 (de) Glasfaserfilter zur Unterdrückung von verstärkter spontaner Emission
EP1067412B1 (de) Dispersionkompensierende optische Faser
EP0753771B1 (de) Monomodaler dispersionsverschobener optischer Wellenleiter mit grosser effektiver Modenfläche
EP1326105B1 (de) Optische Koppler für multimode Pumpe
EP0880038B1 (de) Optische Faser zur Reduktion von optischen Signalreflektionen
EP0355782B1 (de) Nichtanzapfbare optische Monomodefaser und diese Faser verwendendes Übertragungsverfahren
EP0984309A1 (de) Dispersionsverschobene optische Einmodenfaser mit einem äusseren Brechzahl-Ring
FR2523316A1 (fr) Fibre optique a quadruple gaine
EP0992817B1 (de) Dispersionsverschobene monomodige optische Faser mit grosser effektiver fläche
JP4121772B2 (ja) 耐タップ伝送を確実にする構成の光ファイバ
EP1709715B1 (de) Multimoden-lichtfaser
EP0704945B1 (de) Geregelter optischer Verstärker mit optischem Zirkulator
EP0987569A1 (de) Optimierte dispersionsverschobene monomodige optische Faser für hohe Datenraten
EP1217399A1 (de) Glasfaser zur Kompensation der chromatischen Dispersion einer NZ-DSF-Glasfaser mit positiver chromatischer Dispersion
EP1081514A1 (de) Optische Faser zur Kompensation der chromatischen Dispersion einer optischen Faser mit positiver chromatischer Dispersion
EP1030474B1 (de) Übertragungsstrecke und Verfahren zur Übertragung mittels optischer Fasern
EP1018656B1 (de) Optische Faser mit geringem Gradienten der chromatischen Dispersion
EP1030198A1 (de) Optische Faser mit Stufenbrechungsindex und grosser Bandbreite
EP0718647B1 (de) Optische Einmodenfaser
JP3209497B2 (ja) 光減衰性光ファイバ
FR2782390A1 (fr) Fibre optique monomode a dispersion decalee et a creux central
EP1538469A1 (de) Lichtempfindlicher optischer Wellenleiter
Roxana-Mariana et al. ON OPTICAL POWER BUDGETS FOR FIBER OPTICS
Khan et al. Optical fiber-past, present and future: a review
FR2788180A1 (fr) Systeme de transmission a fibre optique a multiplexage en longueur d'onde

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT NL

17P Request for examination filed

Effective date: 19900827

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ALCATEL ALSTHOM COMPAGNIE GENERALE D'ELECTRICITE

17Q First examination report despatched

Effective date: 19920103

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT NL

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 19940126

REF Corresponds to:

Ref document number: 68912684

Country of ref document: DE

Date of ref document: 19940310

ITF It: translation for a ep patent filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: FR

Ref legal event code: CL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19990719

Year of fee payment: 11

REG Reference to a national code

Ref country code: FR

Ref legal event code: CD

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010301

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20010301

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20040730

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20040805

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20040809

Year of fee payment: 16

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050822

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050822

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060301

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20050822

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20060428

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20060428